It's pelican versus trout in predator conflict

More than 4,700 spawning cutthroats were counted in 2001; the number dropped to just 14 in 2005, before rebounding to 540 this spring. Anglers must release cutthroat, because their numbers are so low.

"The pelicans have really lined up on the banks and rocks of the Blackfoot River," Teuscher said, adding 70 percent of surviving fish showed scarring from birds. Hazing efforts, including the use of rumbling ATVs, have proven largely ineffective. Teuscher has begun stocking rainbow trout after pelicans migrate south in the fall.

"It's not the ideal time to stock rainbow trout, but it's the only time to stock them and survive," he said.

Starting in 2007, state wildlife biologists began tagging hundreds of the season's pelican chicks to determine if they return after wintering south — and if wide-ranging pelicans from the Snake River and Blackfoot Reservoir are the same ones anglers at lakes and reservoirs elsewhere in the region complain are making a dent in their fish populations.

Tagging was repeated in mid-July, targeting another 600 birds.

As part of the effort, the Department of Fish and Game assembled a team of three fisheries biologists and three wildlife biologists, including Moulton and Teuscher, to work on a pelican management plan. Ten options were drafted, and the recommended alternatives are now under review.

If the agency's commissioners opt later this year for lethal control measures like oiling eggs, the plan would need approval of the Fish and Wildlife Service. That agency has approved other measures to protect fish, including a 1990s effort in the Columbia River to relocate a population of Caspian terns that were decimating endangered salmon and steelhead numbers, though only after extensive environmental review.

Brad Bortner, the agency's chief of the division of migratory birds and habitat, said he'll likely meet with Idaho officials in September or October to discuss the state's pelican plan, which he has yet to see.

"These birds and these fish evolved together, but they're in a somewhat altered ecosystem," he said. "Whatever happens, we'll have to weigh all the competing interests."

More from msnbc.com First Read: Palin on creationism, Clinton, Fey Ice addict heads for poles, Everest | Trek posts Daily Nightly: Tim McGraw helps neighbors in need Were you paying attention? Take our weekly quiz World Blog: China puts foot down on 'Oba Mao' T-shirts Stimulus tracker: See where millions of dollars went On Twitter: Breaking news updates | Weird and wild

MORE FROM ENVIRONMENT

Environment Section Front

Ice addict aims for poles, Everest in one year Ice trekker posts from Antarctica Hawaii's beaches are being eaten up Clinton: No binding climate treaty likely U.N. report puts dollar value on ecosystems Huge Andes lake is drying up Record high temps are double the lows Warming drives off Cape Cod's namesake Iceberg drifts off island south of Australia Brazil: Big drop in Amazon deforestation Environment Section Front   Add Environment headlines to your news reader: